A common type of well pump for petroleum production has a submersible centrifugal pump and an electrical motor. The pump has a plurality of stages, each stage having an impeller and a diffuser. The motor rotates a shaft extending through the pump, which causes the impellers to rotate to pump the well fluid up the well. Another type of well pump, called a progressive cavity pump, rotates a helical rotor within a stator having a double helical cavity. In both types of pumps, if the well fluid contains gas, the gas is detrimental to the pumping efficiency.
Down hole gas separators are commonly employed with down hole pumps to remove as much gas as feasible from the well fluid flowing into the intake of the pump. In standard down hole gas separators for centrifugal pumps, fluids are drawn into the intake of the separator and spun by way of various components that are intended to propel and separate the lighter gaseous well fluid components from the heavier liquid components. The heavier component is spun to the outer surface of the chamber while the lighter component remains in the central part of the chamber.
In prior art down hole separators, both fluids are propelled into a passive or static crossover. The crossover has a liquid passage that directs liquids back to the center and toward the inlet of the pump. The lighter components are direct back by gas passages toward the exterior of the gas separator for discharge into the casing annulus. Friction losses hinder the movement of the fluids through these passages and reduces the efficiency of the separation.